MONDAY, July 18 (HealthDay News) -- Since their advent in the mid-1990s, powerful antiretroviral therapies have radically improved the life expectancy of HIV-infected patients in the developed world.

Now, research suggests that when made affordable and accessible, the same drug cocktails are equally effective for African patients.

The finding stems from a Canadian research team's investigation -- deemed the largest of its kind to date -- looking at HIV treatment efforts in Uganda. They found that HIV-infected Ugandan patients placed on combination antiretroviral therapy (cART) can expect the same life expectancy as Ugandans who are free of the virus.

"HIV/AIDS has historically been a death sentence in Africa," said study co-author Edward J. Mills, the Canada Research Chair in Global Health at the University of Ottawa. "But now we know that effective therapies, provided in a simplified and decentralized manner, can offer very favorable treatment effects in the African context in terms of reducing mortality and improving life expectancy."

Based on other recent studies, "we also now know that even in a resource-poor environment such as Africa, these treatments can actually prevent the spread of new infections to other people," Mills added.

His team released their findings online July 18 in advance of publication in the Aug. 16 print issue of the Annals of Internal Medicine.

The authors noted that the current life expectancy for Ugandans who are not infected with HIV hovers around 55 years of age, a figure that trends upwards as residents age.

According to the study, about 200,000 HIV-positive Ugandans are currently on a cART regimen, while an equal number are waiting for such treatment.

To assess the effectiveness of cART in helping HIV-infected Ugandans achieve a longer life span, the authors focused on more than 22,000 HIV patients aged 14 or older who were being cared for at one of 46 different medical facilities across the country.

All of the patients had been first placed on an antiretroviral regimen at some point between 2000 and 2009, and all were tracked through February 2010.

Basic demographic information was collected, including the patient's age when cART was initiated; year of initiation; patient gender; and each patient's disease stage and clinical status at treatment launch.

By the study's conclusion, an estimated 1,943 patients had died. Nevertheless, the investigators found that Uganda's antiretroviral patients could generally expect to live just as long as non-infected citizens.

Specifically, that meant that HIV-positive Ugandans on a cART regimen were found to have a life expectancy of somewhere between about 47 and 63 years.

Not all patients fared equally well, of course. For example, life expectancy among Ugandan cART patients diverged greatly according to gender, with female patients living significantly longer than male patients. While a 20-year-old Ugandan woman on cART could expect to live until she was about 50, similarly aged men were expected to survive to roughly 40. For 35-year-old cART patients, those figures rose to about 68 years for women but just 57 years among men.

Why the gender disparity? The authors theorize that in Uganda, HIV-positive women are quicker to seek medical care for their situation than men. As happens in the developed world, the team found that Ugandans who began their antiretroviral routine sooner after diagnosis (typically with less advanced disease) lived markedly longer.

For his part, Dr. Jeffrey Laurence, a professor of medicine and director of the Laboratory for AIDS Virus Research at the Weill Medical College of Cornell University in New York City, described the findings as "really good news."

"We've known for quite some time that life expectancy for HIV patients in resource-rich countries is enormously improved by these medications," said Laurence, who is also the senior scientist for programs at The Foundation for AIDS Research (amfAR). "But, the question has always been could you reproduce this elsewhere? And now we've found that in places such as Uganda, adherence can be very good. People can follow directions and adhere to their medications as well as they can in wealthier countries. And that's wonderful."

Uganda has been in the forefront of African nations in terms of how active their government is in promoting HIV prevention and treatment, Laurence acknowledged. But, "it's still a very poor country in the middle of Africa," he said. "So it is very heartening to see that this is working in the context."

"The challenge now is to sustain this spectacular success," said Dr. David Bangsberg, director of the Massachusetts General Hospital Center for Global Health in Boston.

"That will be very challenging," he noted. "And that is because the therapy is so effective. Because if these patients will now have a normal life expectancy, you have to care for them for another 20 to 30 years, while other people are still becoming infected and adding to the list of those who need this treatment. So, resources become a bigger and bigger question, and gaps in treatment can develop," he pointed out.

"So I would say that even though there has been enormous success so far, we're really at a crossroads," Bangsberg cautioned. "Now we have to see if we are able to sustain this success down the road."

More information

For more on global antiretroviral therapy statistics, visit the World Health Organization.